The Ultimate System in DxD
by Heaven's Ruler
Summary: Sora Yamamoto, a person who was just sleeping a while ago before waking up to what he assumed was just a dream until it all came crashing down. While he was sure everything will be hard and rough in the future, one thing was for sure though. With the Ultimate System by his side, he'll stand at the very summit along with many powerful beings! OCxHarem!


**So, this is going to be one of my first OC stories. Yippee? Not sure how to feel, this idea just came into mind after reading a few novels, watching anime, and reading manga. Though I will definitely do my best, I'm not sure how it's going to turn out. If anyone here that is reading right now is a beta-reader, pm me if you're free.**

 **Also, this isn't a self-insert in case you were wondering. If I were to do a self-insert, I honestly think I would screw myself over.**

 **Anyways, I'll get this story started right now.**

* * *

Blinking my eyes, I stared at the HUD that was right in front of me with a look of disbelief and tremendous surprise.

 **Basic Info:**

 **Full Name: Sora Yamamoto**

 **Eye Color: Blue**

 **Hair: White**

 **Race: Human**

 **[Welcome new host: Sora Yamamoto. You have successfully received the blessing of the Ultimate System. To continue, you may choose between 3 selections of the system that will be listed below.]**

Hmm? Now, this is more interesting. How exactly did I receive a blessing from the supposed Ultimate System? Most likely, this is probably just a dream. A dream that I'm willing to happily enjoy.

 **-Level System**

 **By choosing this system, you can level up by killing monsters, human beings, gods, and any other living things hence upgrading your strength, speed, and stamina easily along with magical reserves. Please keep note that by choosing this system, you will have to stick with it till your very death and you will not come back to life this time around. Another note, killing monsters may also contain drops.**

 **-Death System**

 **By choosing the Death System, you can simply be revived constantly while getting a tiny bit of increase in strength. But please keep note that after death, you will be respawned about an hour earlier to where you were before. Also, this is very limited. Each person/living being you kill will contain Death Points which will revive you until you run out. If you die again and you ran out of points, you will have a fate worse than Death.**

 **-Point System**

 **By choosing the Point System, you can unlock a variety of different abilities, items, and even summons in the point shop depending on how much you earn. Keep note that like the other systems, there will obviously be a mission that can help you gain even more points and even unlock a skill or an ability. By choosing this, you may even be granted access to spin a total of 4 times to get started with your new item, ability, and summon.**

All of them seemed great except for maybe the Death System. After all, if I run out of death points and I die, I will have a fate worse than death? Yeah, no thanks. Not sure I'm willing to pick this and have a nightmare all of a sudden.

The Level System huh? It seemed amazing but there was one problem with it. What's the level cap? What happens if I get slightly stabbed in the toe and all of a sudden im just dead? Yeah, there are disadvantages but also advantages I could take if I pick this. But, it's not what I want.

Lastly, the Point System. Now while I can see the disadvantages of using this, I can also see the major points of using it.

"I choose the Point System," I said staring at the HUD as it changed.

 **[Congratulations on picking the point system! Because you picked the point system, you may have 4 spins to gain items, abilities, and even summons.]**

A slight smile came across my face as I saw the spin button right below the item wheel. Suddenly, the wheel started spinning like crazy, but I was still able to make out some names that it had.

-Three-Pronged Kunai

-Hyorinmaru

-Senbonzakura

-Zangetsu

-Random Devil Fruit

-The Longinus Spear

-Excalibur

-Durandal

A bunch of well-known names of weapons throughout history and weapons that have only ever existed in anime or manga has appeared making me wonder what I'll get. After a minute of waiting, the spinner suddenly stopped.

 **[Congratulations on winning the S-class Vorn Black Bow! Detected Consciousness inside the bow. Would you like to remove it?]**

Hmm? The Black Bow that Tigre used in Lord Marksman? I can't exactly remember the name of the person who's consciousness was in the bow, but I don't really need to have a talking bow now do I?

"Remove it."

 **[Successfully removed the Tir Na Fal from the bow. Please keep note that because of this, the strength of the bow is now weakened just a bit but not to the point it will be degraded to A-class.]**

Huh? So the grade of the weapons can go down?

 **[Yes, it can go down only if you remove what was supposed to originally belong to the weapon.]** The System answered making me instantly regret removing Tir Na Fal.

"Spin." Pressing the button to hopefully find something that would be as good if not better than the Black Bow, I instantly pressed the ability spinner.

 **[Congratulations on receiving the C-class Bow Proficiency! Please note this can be upgraded by collecting a large amount of points or if you can improve your skills to go up a rank.]**

"Bow Proficiency?" I tilted my head looking at this. I was already pretty decent with the bow due to the fact I used to be apart of the Archery club. Although I have to admit, I was only decent at it. I was no god with the bow like Tigre or Archer from Fate/Stay Night. Still, it can be upgraded huh? I wonder how many points it would take.

 **[Due to the request of the host, the system will show you how many points it will take to upgrade your bow proficiency!]**

 **[B-Class Bow Proficiency- 15,000 points, A-class Bow Proficiency- 50,000 points, S-class Bow Proficiency 250,000 points, EX-class Bow Proficiency- Unknown.]**

"?!" What the hell?! How many living things would I have to kill to earn that many points! Especially B-class! Why is it so expensive?!

 **[Please keep note that the world you'll be sent in is unknown. Hence, the number of points you earn for killing something will also be unknown but the system will calculate it's strength and give you the appropriate amount of points.]**

Calming myself down, I nodded at that. I guess it makes sense, but that would still take such a long time to earn all of that.

Sighing to myself I look at the summoning wheel and just clicked spin. After waiting a minute, it finally landed on something that made me surprised.

 **[Congratulations on receiving A-class Aiz Wallenstein! She's about a step away from S-class but that step is as difficult as destroying the heavens itself! Nonetheless, she's a very powerful summon so congratulations host!]**

I could already feel my eye twitching at that. A-class just a step away from S-class but the step was as difficult as destroying the heavens... Why can I already feel that something was really off with this dream?

"Let's just get this over with." I pressed spin slowly waiting for what ability I would get. Will it be the Sharingan? Maybe some Hollow Powers from bleach?! Just thinking about it gets me so exci-

 **[Congratulations on receiving C-class pain immunity! This can be upgraded by enduring an endless amount of pain instead of using points.]**

"..." Looking at this, I almost want to bang my head. I mean, it sounds useful and all, but I'm already used to pain already! Anyone with a normal childhood would already be used to pain!

...I think? Either way, I'm pretty sure if there stood a person next to me, they could sense the massive amount of disappointment I have right now.

 **[You have used all of your spins. The system will begin transmigrating you to Universe Section 669- Highschool DxD.]**

"Huh? Well, that's something I didn't expe-"

Before I could finish what I was saying, I was instantly teleported to what I assume would be DxD. One thing was for sure though, the fact I received a skill called C-class pain immunity...

This was definitely not a dream.

* * *

 **Regular POV**

 **-In an unknown forest-**

"Ugh..." Slowly waking up, the young teen known as Sora Yamamoto opened his silver eyes and got up. Pinching his cheek, he can feel a slight pain confirming his suspicions.

"Eh? This is not a dream?" Looking around, he noticed it was most likely either the morning or the evening right now.

 **[To open the menu, please close your eyes and just say menu.]** A voice suddenly said freaking Sora out as he looked around.

'Was...that the system?' He thought to himself before he proceeded to close his eyes. He was freaked out, but something deep down in his mind was telling him to remain calm. To just focus on one optimal thing.

Survival.

'Menu.' He said in his thoughts as a bright menu appeared in his mind. Although he was confused, he nonetheless began understanding the system.

 **-Current Points: 250**

 **-Store**

 **-Inventory**

 **-Summons**

'Seems pretty basic.' Sora thought as he proceeded to check his inventory. Seeing the black bow inside, he clicked it and the Vorn Black Bow suddenly appeared on his back along with some arrows. Going back to the main menu, he looked at summons for a moment and then pressed it revealing Aiz Wallenstein at the very top.

 **[Do you wish to summon Aiz Wallenstein for a total of 250 points? Please keep note that after doing this, she cannot return back into the summoning menu and will remain in this world forever until she dies.]** Reading this he was hesitant but nonetheless clicked yes.

 **[Current points are now 0. If you wish to gain more, please go out and hunt.]** The system said, but Sora ignored it as he opened his eyes looking at Aiz Wallenstein who was in front of him with her eyes closed and the white magic circle beneath her.

Suddenly, she opened her eyes looking around before staring straight at Sora as if she was analyzing him.

"My name is Aiz Wallenstein, from the Loki Familia and currently your summon. It's nice to meet you, Sora." Aiz introduced herself as Sora gulped staring at the long golden-haired beauty. After all, her beauty was definitely on the very top no matter if it was her world or his world or even DxD where there were countless beauties. Currently right now, she was wearing her battle clothes. But that still didn't make her any less attracting.

"It's nice to meet you too, Aiz." Sora began hesitating a little bit.

"If you don't mind me asking, how did you already know my name?" Sora asked.

"A voice gave me a brief explanation of what happened and how I came here. It gave me one wish so I can go peacefully." Aiz asked softly smiling remembering the wish the system granted her.

"Oh, and what was that wish?" Sora asked genuinely curious. The System gave her a wish? Does that mean it'll give other people he summoned a wish too so they can calmly come here without troubles?

"Please forgive my rudeness, but I will not be answering that." Aiz returned back to her normal self instantly, her smile disappearing.

"I see... I guess I shouldn't have asked something personal. Sorry." Sora apologized before his eyes widened at Aiz. Drawing his bow instantly, he shot an arrow shooting it past Aiz.

 ***BUMP***

 **[Congratulations on killing a Viper! You have earned 25 points!]** The system announced.

"Not bad." Aiz simply said looking at the bow. She had already sensed the viper and was just about to kill it until Sora reacted to the situation immediately.

"Thanks. Right now, we should probably find a way out of this forest. You're more experienced with dungeons, so can you help me?" Sora asked Aiz who nodded. Following her lead, the two encountered not as many wild animals as he would imagine. Although they did kill some and even encounter supernatural beasts and slain them! While it wasn't to the point one can see a bunch of dead bodies lying around together. Neither of the two spoke since they began there search to find the exit since there really wasn't anything that was needed to be said to each other. The two just recently met after all, how can they get so familiar with each other that easily?

After a while, they both finally found a lead that would get them out of the forest before dusk until...

 **[Warning! A being capable of bringing you down to the deepest depths of purgatory is nearby! Suggests host runs as fast as he can away or face the consequences.]**

"Oh you got to be shitting m-"

 **"AWRRRRRRRRRRRRRRRRRR!"** A loud roar was heard shaking the forest and scared many wildlife away. The ground was shaking nonstop most likely due to how big the beasts.

"Aiz!" Yelling at his fellow companion, Aiz nodded and immediately drew her sword while Sora drew his bow.

Slowly, they saw a somewhat big figure walking towards them with an appearance of some sort of brown lizard with armor covering it.

The moment Sora saw it, he immediately fetched an arrow from his holster and shot it straight in the eye.

 ** _BCKK!_**

Only for it to fail. The eye was usually the most sensitive part of any creature but it seemed like this lizard didn't have that weakness. Gritting his teeth, he immediately grabbed another arrow and shot at the same spot again only to see that it didn't work. Aiz also took the same course of action as Sora stabbing it straight in the eye only for her sword to bounce back towards her.

 **"ROARRRRRRRR!"** The beast let out a mighty roar as it was agitated by the two. It finally started it's counter-attack and used it's tail to swipe both Sora and Aiz which the two managed to dodge just in time.

'System, menu open!' Sora immediately went through his mind and closed his eyes. As soon as it opened, he pressed the store and scanned the items and abilities he could buy as fast as he could while Aiz was busy fighting the Earth Lizard.

 **C-Class Heal potion- 2,500 points.**

 **C-Class Sharingan First Stage - 5,000 points. Upgradeable by points or regularly.**

 **A-Class Zangetsu (Fake) - 95,250 points.**

After scrolling for a while and running away at the same time, Sora finally found what he needed. The only problem was Sora was still missing 250 points to buy it.

 **Current Points: 4,250 points.**

 **C-class 10 Enhanced Arrows- 4,500 points.**

 **Description: Can easily pierce through any sort of armor as long as the beings in question aren't above A-class. Note that the damage and the penetration strength of the arrow will be lower if the beings are above C-class.**

Seeing this, he could only grit his teeth and hoped that Aiz could finish the god damn Earth Lizard. If he was right, it should be within A-class, but the weaker part of it.

Suddenly, he heard something loud being cut. Turning his head, he saw Aiz finally managed to wound the Earth Lizard making it roar in pain. Taking the chance after finally seeing that he could possibly damage it further, Sora drew his bow and aimed straight towards the cut that Aiz left the beast with.

 _ **SWOOOOOO!**_

Hitting straight at the wound, the beast let out a shriek of pain and focused its eyes straight at Sora.

 _ **BOOOOM!**_

The Earth Lizard began to swipe its tail straight towards him. Instinctively, he immediately drew his bow and did something that surprised both him and Aiz.

The bow was starting to release a shining dark color and caused the arrow to be strengthened increasing its penetration and strength. The moment Sora shot his arrow, it flew straight towards the tail and went straight through its powerful defenses blasting the tail right off of the Earth Lizard!

 **[Ding! The host has completed the hidden quests: Using the Vorn Black Bows power! Reward: Host is now able to use some the power of the bow** **consciously.]**

Surprised by the sudden announcement yet excited at the time, Sora looked at his bow that kept glowing nonstop. Gripping it in his hand, he took a deep breath before he looked at Aiz who was rushing the lizard alone. Her eyes showed no emotion other than the determination to cut down her enemy. Running towards it, she dodged it's swipe jumping and gracefully landed on top of its head before stabbing it with enough force to create a crater.

 **[Congratulations! Because Aiz has finished the beast known as A-class Earth Lizard for you, half of the points have been taken away and you have earned 7,500 points! Still recommend the host to run away before it's too late.]**

"Originally 15,000 points huh? So right now, I have 11,750 points. But what does it mean that I have to run away before it's too late? Didn't I already took it down?" Sora wondered before suddenly saw a gigantic shadow on the ground.

"Eh?" Both Sora and Aiz looked up only to see a gigantic bird-like being. Unlike usual birds that were made of feather and flesh, this one seems to be made out of flames and if it's red angry eyes were anything to go about, it seemed pretty angry.

"Oh please tell me it's not what I think it is," Sora whispered only for the Ultimate System to plunge him into eternal despair while Aiz just stared at the phoenix her eyes widened in surprise.

"Beautiful..." She whispered looking at the angry phoenix. In all of her years of living, she had basically seen the most beautiful animals the gods had to offer and even in the dungeons. But this Phoenix was definitely...

Majestic.

 **[Emergency! Host has encountered the King of the Phoenixes! Recommend host to buy a teleport crystal and escape right away or else you and your summon will be nothing but ashes! Warning: The system detects that you are probably currently facing an S-class being who should be ranked top 250 in out of every being in this universe. Any attacks from both host and summon will not affect the immortal bird until you reach S-class.]**

Without any hesitation after hearing the system, Sora grabbed Aiz hand and ran away. The two dashed jumping over a few branches and a few obstacles blocking them from moving forward.

 **"SYSTEM MENU OPEN! VOICE COMMAND BUY TELEPORT CRYSTAL!"** Sora ran away as fast as he could while yelling. Sweat all over his body tightening his clothing a bit both from the intensity of the heat coming from the Phoenix and the amount of stamina he used while finding an exit from the forest and the battle he had with the earth lizard. If he were to enter the system while closing his eyes, that'll be a death sentence. So running away, he hoped there was such thing as a voice command in the system or else he and Aiz were both doomed.

 **[System buying C-class Teleport Crystal. Item will appear in your inventory right away. Current remaining points: 5,750. To use the teleport crystal, just simply say teleport then the name of where you wish to go.]**

 _ **SCREEECHHHH!**_

Hearing a loud yet beautiful screech, Sora turned around only for his eyes to be filled with horror. The Phoenix raised its head up proudly and spewed out the strongest flamethrower he had ever seen in his lifetime. Feeling the immense amount of heat that was coming towards both him and Aiz, he reacted immediately.

Quickly, he let go of Aiz's hand and drew his bow powering up his arrow as best as he can. Feeling what he assumed was magic and energy draining from his body, he released his fingers as the arrow shot towards the Phoenixes flamethrower. If this was anything like the show from Vanadis, the arrow should be strong enough to counter the flamethrower because he used as much energy and magic as he could into that shot. Not to mention that his bow itself was an S-class item so it should be enough to stall some time for them to use the teleport crystal.

Quickly he popped his menu as fast as he could while the clash was still going on and pulled out a blue rectangular crystal from his inventory while raising it in the air.

"Teleport, England!" Sora shouted placing his bow back on his back and wrapped his arms around Aizs' waist pulling her closer towards him. Like that the two disappeared in a blue light just when the clash between the Phoenixes flamethrower and the magic arrow ended.

Looking around, the Phoenix narrowed its eyes before it let out a loud screech of anger due to the fact Sora and Aiz had escaped its grasp. After looking around for a minute, it decided to just leave it. After all, there was no point in wasting time on something like this.

* * *

 **Chapter 1 done!**

 **Teleport Crystals cost 6,000 by the way. Fair enough price I'd say.**

 **I picked Aiz by basically using wheeldecide which spun multiple characters from many other animes like Bell Cranel, Akame from Akame Ga Kill, and all that. Hell even got Happy from Fairy Tail on here.**

 **Got a quick question for everyone here, but who do you think in all of the animes you watched deserve to be in the EX-class?**

 **Rankings:**

 **F-Class Mundane items/abilities that don't really damage anyone or doesn't have magic mixed into it. There are times when it can be helpful though and shouldn't be left out for sure.**

 **D-Class**

 **C-Class**

 **B-Class**

 **A-Class**

 **S-Class**

 **EX-Class**

 **. Anyways, that's how it is. Sora will have a harem, I'm just not sure who I will put in but I do got some.**

 **Sora Harem: Aiz Wallenstein (Is it wrong to pick girls up in a dungeon?), Kuroka, and Rossweisse. Still thinking of more, but yeah. That's all for now. Might add Koneko or Akeno in.**

 **In future chapters, I will dive deeper into the system's capabilities and what fits into what class like F-class, D-class and all that. For now though, just know that anything above C-class is enough to save a person's life while D-class and F-class have barely any effect in battle.**

 **Next chapter will basically be somewhat basic. I'm having the next chapter dive into Sora's personality so you guys can get a better understanding of who he is, and what he'll likely do, and likely won't do. Aiz as well too, but it won't be just as much as Sora considering he's the main character here. Don't worry though, the difference won't be too huge.**

 **Also, for those who came here from my other stories like Red Dragon Guardian and all that, I'll list the percentage of each chapter below and how close they are to finishing.**

 **Red Dragon Guardian: 20%**

 **The God of Shinobi in DxD 75%**

 **The Yellow Flash of Fairy Tail REWRITTEN!: I'd say 35%?**

 **Yeah, that's about it.**


End file.
